In this protocol, we report an allylic defluorinative reductive cross-coupling reaction for C–C bond formation. Under the Ni-catalysis the challenging C(sp3)–F bond cleavage of ...trifluoromethyl-substituted alkenes was achieved with easily accessible primary, secondary and tertiary alkyl halides as the coupling partners and Zn-powder as reducing agent. This process provides an efficient and convenient entry to gem-difluoroalkenes bearing various sensitive functional groups under mild reaction conditions. Moreover, this method proves to be suitable for late-stage functionalization of multifunctional complex molecules.
A high-efficient, low-cost, and eco-friendly catalyst is highly desired to activate peroxides for environmental remediation. Due to the potential synergistic effect between bimetallic oxides’ two ...different metal cations, these oxides exhibit superior performance in the catalytic activation of peroxymonosulfate (PMS). In this work, novel Mn1.8Fe1.2O4 nanospheres were synthesized and used to activate PMS for the degradation of bisphenol A (BPA), a typical refractory pollutant. The catalytic performance of the Mn1.8Fe1.2O4 nanospheres was substantially greater than that of the Mn/Fe monometallic oxides and remained efficient in a wide pH range from 4 to 10. More importantly, a synergistic effect between solid-state Mn and Fe was identified in control experiments with Mn3O4 and Fe3O4. Mn was inferred to be the primary active site in the surface of the Mn1.8Fe1.2O4 nanospheres, while Fe(III) was found to play a key role in the synergism with Mn by acting as the main adsorption site for the reaction substrates. Both sulfate and hydroxyl radicals were generated in the PMS activation process. The intermediates of BPA degradation were identified and the degradation pathways were proposed. This work is expected to help to elucidate the rational design and efficient synthesis of bimetallic materials for PMS activation.
Although pyroptosis is critical for macrophages against pathogen infection, its role and mechanism in cancer cells remains unclear. PD-L1 has been detected in the nucleus, with unknown function. Here ...we show that PD-L1 switches TNFα-induced apoptosis to pyroptosis in cancer cells, resulting in tumour necrosis. Under hypoxia, p-Stat3 physically interacts with PD-L1 and facilitates its nuclear translocation, enhancing the transcription of the gasdermin C (GSDMC) gene. GSDMC is specifically cleaved by caspase-8 with TNFα treatment, generating a GSDMC N-terminal domain that forms pores on the cell membrane and induces pyroptosis. Nuclear PD-L1, caspase-8 and GSDMC are required for macrophage-derived TNFα-induced tumour necrosis in vivo. Moreover, high expression of GSDMC correlates with poor survival. Antibiotic chemotherapy drugs induce pyroptosis in breast cancer. These findings identify a non-immune checkpoint function of PD-L1 and provide an unexpected concept that GSDMC/caspase-8 mediates a non-canonical pyroptosis pathway in cancer cells, causing tumour necrosis.
Inflammation-related parameters have been revealed to have prognostic value in multiple caners. However, the significance of some inflammation-related parameters, including the peripheral blood ...neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR) and prognostic nutritional index (PNI), remains controversial in T1-2 rectal cancer (RC).
Clinical data of 154 T1-2 RC patients were retrospectively reviewed. The cut-off values for NLR, PLR, LMR, and PNI were determined by receiver operating characteristic curves. The relationships of these parameters with postoperative morbidities and prognosis were statistically analysed.
The optimal cut-off values for preoperative NLR, PLR, LMR and PNI were 2.8, 140.0, 3.9, and 47.1, respectively. Significant but heterogeneous associations were found between NLR, PLR, LMR and PNI and clinicopathological factors. In addition, high NLR, high PLR, and low PNI were correlated with an increased postoperative morbidity rate. Patients with high NLR/PLR or low LMR/PNI had lower OS and DFS rates. On multivariate analysis, only high NLR was identified as an independent risk factor for poor DFS.
NLR, PLR, and PNI are valuable factors for predicting postoperative complications in T1-2 RC patients. A preoperative NLR of more than 2.8 is an independent prognostic factor for poor DFS in T1-2 RC patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Regional ocean–atmospheric interactions in the summer tropical Indo–northwest Pacific region are investigated using a tropical Pacific Ocean–global atmosphere pacemaker experiment with a coupled ...ocean–atmospheric model (cPOGA) and a parallel atmosphere model simulation (aPOGA) forced with sea surface temperature (SST) variations from cPOGA. Whereas the ensemble mean features pronounced influences of El Niño–Southern Oscillation (ENSO), the ensemble spread represents internal variability unrelated to ENSO. By comparing the aPOGA and cPOGA, this study examines the effect of the ocean–atmosphere coupling on the ENSO-unrelated variability. In boreal summer, ocean–atmosphere coupling induces local positive feedback to enhance the variance and persistence of the sea level pressure and rainfall variability over the northwest Pacific and likewise induces local negative feedback to suppress the variance and persistence of the sea level pressure and rainfall variability over the north Indian Ocean. Anomalous surface heat fluxes induced by internal atmosphere variability cause SST to change, and SST anomalies feed back onto the atmosphere through atmospheric convection. The local feedback is sensitive to the background winds: positive under the mean easterlies and negative under the mean westerlies. In addition, north Indian Ocean SST anomalies reinforce the low-level anomalous circulation over the northwest Pacific through atmospheric Kelvin waves. This interbasin interaction, along with the local feedback, strengthens both the variance and persistence of atmospheric variability over the northwest Pacific. The response of the regional Indo–northwest Pacific mode to ENSO and influences on the Asian summer monsoon are discussed.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
NiFe-layered double hydroxide (NiFe LDH) is a state-of-the-art oxygen evolution reaction (OER) electrocatalyst, yet it suffers from rather poor catalytic activity for the hydrogen evolution reaction ...(HER) due to its extremely sluggish water dissociation kinetics, severely restricting its application in overall water splitting. Herein, we report a novel strategy to expedite the HER kinetics of NiFe LDH by an Ir4+-doping strategy to accelerate the water dissociation process (Volmer step), and thus this catalyst exhibits superior and robust catalytic activity for finally oriented overall water splitting in 1 M KOH requiring only a low initial voltage of 1.41 V delivering at 20 mA cm−2 for more than 50 h.
Diabetic wounds are recalcitrant to healing. However, the mechanism causing this dysfunction is not fully understood. High expression of matrix metalloproteinase-9 (MMP-9) is indicative of poor wound ...healing. In this study, we show that specificity protein-1 (Sp1), a regulator of MMP-9, binds directly to its promoter and enhances its expression. Additionally, we demonstrated that Sp1 is the direct target of two microRNAs (miRNAs), miR-129 and -335, which are significantly downregulated in diabetic skin tissues. In vitro experiments confirmed that miR-129 or -335 overexpression inhibits MMP-9 promoter activity and protein expression by targeting Sp1, whereas the inhibition of these miRNAs has the opposite effect. The beneficial role of miR-129 or miR-335 in diabetic wound healing was confirmed by the topical administration of miRNA agomirs in diabetic animals. This treatment downregulated Sp1-mediated MMP-9 expression, increased keratinocyte migration, and recovered skin thickness and collagen content. The combined treatment with miR-129 and miR-335 induced a synergistic effect on Sp1 repression and MMP-9 downregulation both in vitro and in vivo. This study demonstrates the regulatory mechanism of Sp1-mediated MMP-9 expression in diabetic wound healing and highlights the potential therapeutic benefits of miR-129 and -335 in delayed wound healing in diabetes.
Microbial extracellular polymeric substances (EPS) widely exist in natural environments and affect the migration and transformation of pollutants in aquatic environments. Previous works report that ...EPS have some reducing functional groups and can reduce heavy metals. However, because of the weak reducing capability of EPS, the reduction of heavy metals by EPS without cells is extremely slow, and its effect on heavy metals species is insignificant. In this work, the accelerated reduction of silver ions (Ag+) by EPS from Shewanella oneidensis MR-1 under illumination was investigated. UV–visible spectroscopy, transmission electron microscopy (TEM) coupled with an energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) were used to confirm the formation of silver nanoparticles (AgNPs) via the reduction of Ag+ by EPS under light illumination. The Ag+ reduction by EPS follows pseudo-first-order kinetics under both visible and UV light, and the light irradiation can significantly accelerate AgNPs formation. On the one hand, visible light can excite AgNPs for their surface plasma resonance (SPR) and accelerate the electrons from the EPS to adjacent Ag+. On the other hand, EPS molecules may be excited by UV light to produce strong reducing species, which enhance Ag+ reduction. Moreover, pH, dissolved oxygen were found to affect the formation of AgNPs by EPS. This work proves the reducing capability of EPS on the reduction of Ag+, and this process can be accelerated under light illumination, which may affect the speciation and transformation of heavy metals in natural waters.
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•AgNPs formation via reduction of Ag+ by EPS under illumination was confirmed.•Light illumination can significantly enhance the reduction of Ag+ by EPS.•The Ag+ reduction by EPS follows pseudo-first-order kinetics.•The mechanism of effect of light on the reduction of Ag+ by EPS was proposed.•pH and dissolved oxygen will influence the reduction of Ag+ by EPS.
The construction of bifunctional highly active and durable electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is attractive and challenging for overall water ...splitting. Herein, we reported a Ni–Co phosphide @phosphate nanocages (NCPP NCs) catalyst prepared by phosphorization of Ni–Co layered double hydroxide (Ni–Co LDH) with in-situ formation of phosphate. The NCPP NCs exhibited an improved wettability with a contact angle of approximately 0° compared with those of Ni–Co LDH (52°) and nickel-cobalt phosphides (NiCoP) (99°). NCPP NCs have been used for enhancing the water-splitting efficiency, and it only required the overpotentials of 291 mV and 140 mV for OER and HER in 0.1 M KOH to achieve the current densities of 10 mA cm−2, respectively. Impressively, the overpotential of NCPP NCs decreased by 42 mV and 64 mV at 10 mA cm−2 for OER in comparison with those of RuO2 and NiCoP (without phosphate phase). Consequently, NCPP NCs, as the bifunctional catalysts, displayed an outstanding performance for the whole water-splitting process with a small potential of 1.60 V at 10 mA cm−2 and long-term stability. These performances enabled this material to be a promising catalyst for overall water electrolysis.
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•NCPP, as bifunctional catalysts, were prepared by phosphorization of Ni–Co LDH.•NCPP NCs exhibited excellent OER and HER performances.•NCPP NCs exhibited superior whole water-splitting activity and excellent cycling stability.
Abstract
Objectives
We aim to detect demographic history and early farming‐related migration of the crossroad area in the junction of east Asia (EA) and southeast Asia (SEA).
Materials and methods
We ...collected and genotyped 87 individuals from 6 Tibeto‐Burman and Austroasiatic‐speaking populations including Bai, Pumi, Hani, Lahu, Wa, and Blang with nearly 700,000 genome‐wide SNPs. We subsequently analyzed genetic structure and admixture using our merged dataset including both ancient and modern eastern Eurasians with PCA, ADMIXTURE,
Refine
‐IBD,
f
statistics and
qpAdm
.
Results
We observed population substructure within the studied Tibeto‐Burman populations. The northern Tibeto‐Burman groups (Bai and Pumi) had a predominant genomic legacy associated to millet‐farming from North China and also high frequencies of Y‐chromosomal haplogroup O2a2b1‐M134 (xM117) and its sub‐clades. By contrast, southern Tibeto‐Burman groups (Lahu and Hani) had more than 60% genomic legacy associated to rice‐farming, which is prevalent in present‐day Tai‐Kadai, Austronesian and Austroasiatic speaking populations. We observed strong genetic affinities between Austroasiatic populations in Yunnan (Blang and Wa) and mainland southeast Asia.
Discussion
Our study revealed that both demic migrations and cultural interactions from north to south and east to west since the Late Neolithic have shaped the genetic structure of populations at the crossroads of EA and SEA. The dominant genomic legacy associated with millet‐farming in northern Tibeto‐Burman populations indicates large‐scale Neolithic migrations from the Upper‐Middle Yellow River Basin. The rice‐farming expansion has deeply influenced the genetic profile of both southern Tibeto‐Burman and Austroasiatic populations, suggesting migrations from east to west via both inland and coastal routes.
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